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Costs and effects of screening and treating low risk women with a singleton pregnancy for asymptomatic bacteriuria, the ASB study

Brenda M Kazemier1*, Caroline Schneeberger2, Esteriek De Miranda1, Aleid Van Wassenaer3, Patrick M Bossuyt4, Tatjana E Vogelvang5, Frans JL Reijnders6, Friso MC Delemarre7, Corine JM Verhoeven8, Martijn A Oudijk9, Jeanine A Van Der Ven10, Petra N Kuiper11, Nicolette Feiertag12, Alewijn Ott13, Christianne JM De Groot14, Ben Willem J Mol1 and Suzanne E Geerlings2

Author Affiliations

1 Department of Obstetrics and Gynaecology, Academic Medical Centre, Amsterdam, the Netherlands

2 Department of Infectious Diseases, Centre for Infection and Immunity Amsterdam (CINIMA), Academic Medical Centre, Amsterdam, the Netherlands

3 Department of Neonatology, Emma Children’s Hospital Academic Medical Centre, Amsterdam, the Netherlands

4 Department of Clinical Epidemiology, University of Amsterdam, Amsterdam, the Netherlands

5 Department of Obstetrics and Gynaecology, Diakonessenhuis Utrecht, Utrecht, the Netherlands

6 Department of Obstetrics and Gynaecology, Slingeland Hospital, Doetinchem, the Netherlands

7 Department of Obstetrics and Gynaecology, Elkerliek Hospital, Helmond, the Netherlands

8 Department of Obstetrics and Gynaecology, Máxima Medical Centre, Veldhoven, the Netherlands

9 Department of Obstetrics and Gynaecology, University Medical Centre Utrecht, Utrecht, the Netherlands

10 Ultrasound centre Espérance, Arnhem, the Netherlands

11 Ultrasound centre FARA, Ede, the Netherlands

12 Ultrasound centre VCO echopunt, Amsterdam, the Netherlands

13 Laboratory for infectious diseases, Groningen, the Netherlands

14 Department of Obstetrics and Gynaecology, VU Medical Centre, Amsterdam, the Netherlands

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BMC Pregnancy and Childbirth 2012, 12:52  doi:10.1186/1471-2393-12-52

Published: 21 June 2012



The prevalence of asymptomatic bacteriuria (ASB) in pregnancy is 2-10% and is associated with both maternal and neonatal adverse outcomes as pyelonephritis and preterm delivery. Antibiotic treatment is reported to decrease these adverse outcomes although the existing evidence is of poor quality.


We plan a combined screen and treat study in women with a singleton pregnancy. We will screen women between 16 and 22 weeks of gestation for ASB using the urine dipslide technique. The dipslide is considered positive when colony concentration ≥105 colony forming units (CFU)/mL of a single microorganism or two different colonies but one ≥105 CFU/mL is found, or when Group B Streptococcus bacteriuria is found in any colony concentration. Women with a positive dipslide will be randomly allocated to receive nitrofurantoin or placebo 100 mg twice a day for 5 consecutive days (double blind). Primary outcomes of this trial are maternal pyelonephritis and/or preterm delivery before 34 weeks. Secondary outcomes are neonatal and maternal morbidity, neonatal weight, time to delivery, preterm delivery rate before 32 and 37 weeks, days of admission in neonatal intensive care unit, maternal admission days and costs.


This trial will provide evidence for the benefit and cost-effectiveness of dipslide screening for ASB among low risk women at 16–22 weeks of pregnancy and subsequent nitrofurantoin treatment.

Trial registration

Dutch trial registry: NTR-3068